Enitity Component System¶

What Is ECS?¶

How ECS Is Fast?¶

let understand what is the actual problem & how ecs solve it

Modern CPUs are insanely fast at math but painfully slow at memory access

because RAM is slow cpu used cache for storing small data to process.

But the problem with OOPS in traditional Object-Oriented Programming (OOP), you organize code by Objects.

eg:

class model {
    std::string modelName;     // owns heap memory (dynamic memory)
    std::vector<double> pose;  // owns heap memory (dynamic memory)
    float size[3];             // inline
    float scale[3];            // inline
};

/* 
   modelObj is contiguous in memory.
   However, std::string and std::vector store their data on the heap,
   causing pointer indirection and non-contiguous access patterns,
   which reduces cache efficiency in tight loops.
*/
model modelObj[2]; 

but modelName & pose are discontinuous memory because of these it cause trouble to caching
The core problem is CPU cache inefficiency caused by memory layout

ECS Continuous Memory¶

ECS we just control components & read/write on them one by one

First loop on modelName components, than loop on all Pose components
Because of component now continuous memory is allocated